Is this legitimate

I know this is a Dell forum, and I am a newbie, so I am not sure if this is legitimate or not. I posted my first post, and received a private message that said "Hello, I’m your Dell virtual assistant. I see you've opened a thread. In order for me to review your system configuration, may I have the Service Tag / Express Service Code?"

Is this legit? Or is someone trying to scam my service tag/express service code? Can they hijack my machine with that info? I am really technologically handicapped, LOL, so I thought I'd ask the resident experts -- thanks in advance.